Agilent Technologies Infiniium 90000 A Service Manual page 64

Chapter 4: Troubleshooting
Under-Voltage Fault
Figure 4-10
This figure shows how to measure the backplane assembly resistance between +12V and ground across Q1409.
If the oscilloscope still will not power on after you have followed the required steps in this
Power Supply Trouble Isolation section (and assuming you have looked through the other two
sections included in this Power Supply Trouble Isolation section to ensure your problem cannot
be fixed there), refer to the Motherboard Verification section in this chapter for additional
diagnosis suggestions.
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